Leveraging gait dynamics to improve efficiency and performance of powered hip exoskeletons

This paper presents a new mechanical design for efficient exoskeleton actuation to power the sagittal plane motion in the human hip. The device uses a DC motor to drive a Scotch-Yoke mechanism and series elasticity to take advantage of the cyclic nature of human gait and to reduce power and control requirements of the exoskeleton. The mechanism creates a transmission that varies between 4:1 and infinity and does not require the motor to reverse direction when the hip joint reverses direction. This paper provides a detailed analysis of how the dynamic nature of human walking can be leveraged with this hip exoskeleton design.